flashing for vent roof penetrations

I'm about to finish my DWV install by taking the vents through the roof. I have purchased some Oatey plastic roof jacks w/ a rubber/neoprene boot that goes around the pipe.

Are there any secrets/tricks to:
1. cutting the hole through the roof (I'm assuming I want the hole as small as possible w/minimum impact to the shingles?
2. attaching the roof jack?
3. getting the roof jack layered under the shingles (do I just stick the top under the shingle above the vent and lay the sides and bottom over the shingles?)
4. sealing the roof jack at sides,bottom, top, fastener penetrations?
5. sealing the roof jack around the pipe?

That's the general idea. Remember that the hole needs to be oval shaped, not round. Always follow the basic principle that flashing must overlap in the downhill direction. It is always the flashing that makes something waterproof. The Henry's is just for backup.

say if you are shingleing a new roof. get the top of the finished part of the shingle up to the bottom of pipe. install boot. nail were the nails will be covered. continue with shingle. if the boot doesnt lay nice throw nails in the corners of exposed area. boots are called "no caulk" so you dont need any sealant unless you want. if you use tar. have a rag dipped in thinner to smooth. one trick is to oversize the hole and use the boot to level the pipe. nothing worse than a pipe thru the roof on an angle! use regular roof nails and no sealant at pipe.